Zoysia japonica L. plant named &#39;SS-Z15&#39;

ABSTRACT

A new and distinct cultivar of  Zoysia  grass named ‘SS-Z15’, is characterized by its wide leaf blade, long white inflorescences, slow lateral growth and good cold hardiness, compared to other  Zoysia  grass cultivars.

LATIN NAME OF THE GENUS AND SPECIES

The Latin name of the genus and species of the novel cultivar disclosedherein is Zoysia japonica L. and therefore characterizes a new anddistinct perennial cultivar of Zoysia.

VARIETY DENOMINATION

The inventive cultivar of Zoysia japonica L. disclosed herein has beengiven the variety denomination ‘SS-Z15’.

BACKGROUND OF THE INVENTION

The present invention relates to a new and distinct perennial cultivarof Zoysia japonica L., hereinafter referred to by the cultivarname‘SS-Z15’.

‘SS-Z15’ is the selection of Zoysia japonica chosen at the Sod Solutionsresearch center in 2008. The exact pedigree is unclear as the plant wasselected in the proximity of two Zoysia grasses including the purplestemmed japonica ‘Meyer’ Zoysia and ‘BK-9’ Zoysia, which is Z.japonica×Z. tenufolia. ‘SS-Z15’ was selected due to a distinct greenstem and relative short leaf blades that were light green color.‘SS-Z15’ has been evaluated in FL, TX, NC, KY and MS in test plot areasduring 2009. The primary characteristics of the ‘SS-Z15’ are coursetexture, wide leaf blade, relative short blades compared to the width,long white inflorescence and a pale color seed head. ‘SS-Z15’ hasdemonstrated excellent fall color retention, good cold hardiness andgreen stolons. The rate of growth is good with average aggressivenesswhich is beneficial to a low maintenance grass. In field applications,‘SS-Z15’ has faster runner growth rates than ‘Meyer’. ‘SS-Z15’ is soidentified in pictures and morphological and agronomic charts of thisdisclosure.

‘SS-Z15’ has been found to retain its distinctive characteristicsthrough successive asexual propagations.

SUMMARY OF THE INVENTION

‘SS-Z15’ is a distinctive cultivar of Zoysia japonica L. having a lightgreen color, relative course leaf texture, long white inflorescence,average lateral growth rates and good cold tolerance. ‘SS-Z15’ ispropagated by sprigs, rhizomes, plantlets, and/or turf sod. ‘SS-Z15’ isestimated to be adapted for use in zones 7-11 of the Plant Heat ZoneMap.

BRIEF DESCRIPTION OF THE FIGURES

This new Zoysia is illustrated by the accompanying photographs whichshow the plant's form, foliage and inflorescences. The colors shown areas true as can be reasonably obtained by conventional photographicprocedures. Colors in the photographs may differ slightly from the colorvalues cited in the detailed botanical description, which accuratelydescribe the colors of the new Zoysia.

FIG. 1. shows ‘SS-Z15’ planted in pots at green-house in a researcharea; Starkville, Miss. ‘SS-Z15’ is shown in the middle, ‘Meyer’ Zoysiaon the right and ‘BK-9’ on the left.

FIG. 2 shows ‘SS-Z15’ pot for evaluation inside a green-house nearStarkville, Miss.

FIG. 3 shows the leaf detail of ‘SS-Z15’.

FIG. 4 shows the stolon/internode detail of ‘SS-Z15.

FIG. 5 shows the inflorescences of ‘SS-Z15’.

FIG. 6 shows flower structures of ‘SS-Z15’ blended in the canopy.

FIG. 7 shows ‘SS-Z15’ field showing overall green color

DETAILED BOTANICAL DESCRIPTION

The following is a detailed description of the new Zoysia grasscultivar, based upon observations of the plant grown in field plots at aresearch area located near Starkville, Miss. ‘SS-Z15’ is an outstandingZoysia grass cultivar with a unique light green color, green stems withno purple runners making it an attractive monolithic grass. ‘SS-Z15’performs better in warmer climates and although it has good coldtolerance is best suited for Plant Heat Zones 7-11. ‘SS-Z15’ is a lowermaintenance grass due to its reduced aggressiveness and its relativelower density than other Zoysia japonica varieties.

Dimensions of Morphological Structures

‘SS-Z15’ was compared to three other Zoysia grass cultivars in a studyplanted near Starkville, Miss. starting in August 2010. Each cultivarwas planted in 1 gallon pots, using potting mix: Redi-earth Plug andSeedling Mix (Sungro Horticulture, Bellevue, Wash.) and were kept at agreen-house to produce plant material for morphological evaluations.Plant material was collected using a random experimental design with 4replications (pots). The greenhouse complex provided natural sunlightconditions. The pots were allowed to grow for four weeks, and then theplants were clipped once to encourage density and stolon development.The plants were allowed to grow un-mowed for another 4 weeks beforemeasurement. The leaf blade measurements were conducted from Aug. 26,2010 through Oct. 7, 2010. Seventy randomly selected leaf blades fromeach cultivar were measured for length and width. Width was measured atthe widest point of the blade. The internode measurements were conductedfrom Nov.1-12, 2010. All the stolons that grew off each pot were used tomeasure the internode diameter and internode length. The inflorescencemeasurements were conducted from Dec. 14, 2010 through Mar. 2, 2011.Twenty five seed-heads were randomly selected from each cultivar. Threeflorets were randomly selected from each head for measurement. FIG. 1and FIG. 2 show the plants in greenhouse during evaluation.

The Analysis of Variance (ANOVA) indicated that cultivars differedsignificantly for most variables measured (Table 1).

TABLE 1 Analysis of Variance for comparison of ‘SS-Z15’ with otherZoysia grass cultivars conducted during the 2010 and 2011 growingseasons. Mean Squares of the traits Source ID (mm) IL (mm) LL (mm) LW(mm) TIL (mm) FRL (mm) PL (mm) NSI SL (mm) Cultivar 12.1** 1986.9*20231.6** 1128.4** 34684.1** 2854.8** 17989.1** 2265.6** 9.42* Error0.09 69.30 316.81 0.203 187.6 12.28 161.8 21.15 0.06 CV 17.18 34.6023.99 12.63 14.61 13.91 18.56 19.56 8.58 ID—Internode Diameter,IL—Internode Length, LL—Leaf Length (mm), LW—Leaf Width (mm), TIL—TotalInflorescence Length, FRL—Floral Region Length, PL—Peduncle Length,NSI—Number of Spikelets per Inflorescence, SL—Spikelet Length.*Significant at 5% level **Significant at 1% level

The cultivars showed significant differences on many of the analyzedmorphological characteristics (Table 1). Internode Diameter (ID),Internode Length (IL), Leaf Length (LL), Leaf Width (LW), TotalInflorescence Length (TIL), Floral Region Length (FRL), Peduncle Length(PL) and Number of Spikelets per Inflorescence (NSI) were significantlydifferent at 1% level (Table 1). Spikelet Length (SL) was significantlyat 5% level (Table 1). The evaluations were well conducted and producedreliable results as demonstrated by the low Coefficients of Variation(CV) (Table 1).

‘SS-Z15’ has a larger internode diameter (2.20 mm) when compared to ‘ElToro’ and the other cultivars used as comparisons (Table 2). ‘El Toro’is the cultivar that looks most similar to ‘SS-Z15’ with naked eye, inthat both cultivars are considered to have ‘coarse texture’ (FIG. 3).‘SS-Z15’ also has the widest leaf blade width (5.10 mm) among the testedcultivars (Table 2). ‘El Toro’ was the cultivar with the second widestleaf blade width (Table 2), but still significantly different from‘SS-Z15’. The leaf blade width difference between the two cultivars was0.9 mm; which is greater than 0.2 mm, the least significant difference(LSD) at 5% level (Table 2).

TABLE 2 Zoysia cultivar comparisons with ‘SS-Z15’ conducted during 2010.Internode Leaf Blade Cultivar Diameter (mm) Length (mm) Width (mm)Length (mm) ‘SS-Z15’ 2.2 25.8 5.1 83.4 ‘El Toro’ 2 30.2 4.2 80.1 ‘BK-9’1.4 23.3 2 48.8 ‘Meyer’ 1.6 18 3 84.4 LSD(0.05) 0.1 2.6 0.2 5.9

‘SS-Z15’ has a light green stolon similar to ‘BK-9’ and ‘Meyer’ (FIG.4). Other distinctive characteristics of ‘SS-Z15’ are its large diameterand long internode. Table 2 shows ‘El Toro’ with the longest internodelength (30.2 mm) and ‘SS-Z15’ with the second longest internode length(25.8 mm) among the tested cultivars. The difference between ‘El Toro’and ‘SS-Z15’ (4.4 mm) was statistically different at the 1% level (Table1). ‘SS-Z15’ also exhibits the largest internode diameter (2.2 mm), whencompared to ‘BK-9’, ‘El Toro’ and ‘Meyer’ (Table 2). ‘El Toro’ exhibitedthe second largest internode diameter (2 mm), but still with adifference (0.2 mm) statistically different at the 5% level (Table 2).

Narrow and short leaf blades in combination with small internodediameter and short internode length (Table 2) provide ‘SS-Z15’ with afine and dense aesthetic look. Normally, fine bladed Zoysias are spikedto the touch, making it unpleasant to step on or lay on top of. Despitehaving relative short blades length to width and short internodes,‘SS-Z15’ is soft to the touch, providing a pleasant feeling when steppedon and touched.

Furthermore, short and narrow leaf blades (Table 2) enable ‘SS-Z15’ toproduce less scalping when maintained with a rotary mower, when other socalled ‘fine bladed’ Zoysias have to be maintained with reel mower toavoid scalping, due to longer and wider leaf blades.

‘SS-Z15’ has very large inflorescences, particularly long seed-heads(floral region) and peduncles (FIG. 5) compared to other Zoysiacultivars. The total inflorescence structure easily stands out in theplant canopy, making it difficult to be spotted and seeing by a personwalking the field. The result is a more pleasant look of the grassfield, with the predominant green color from the leaves and not thepurple color from the floral structure (See, FIG. 7).

A more detailed examination of the inflorescence structures (See, FIG.6), shows ‘SS-Z15’ has the longest floral region (36 mm) and peduncle(88.7 mm), compared to ‘Meyer’, ‘El Toro’ and ‘BK-9 (Table 3). As aresult, the total inflorescence length of ‘SS-Z15’ (124.7 mm) is thelongest among all tested cultivars (Table 3). The cutlivar with thesecond longest inflorescence structure is ‘El Toro’, with floral regionlength of 31.1 mm, peduncle length of 86.1 mm and total inflorescence of117.3 mm (Table 3). Floral region length, peduncle length and totalinflorescence length of ‘SS-Z15’ were statistically different than therespective floral structures of ‘Meyer’, ‘El Toro’ and ‘SS-Z15’ (Table3). In addition of having the longest total inflorescence among thecompared cultivars, ‘SS-Z15’ had the longest spikelet length (3.7 mm)compared to the other cultivars (Table 3). ‘SS-Z15’ spikelet length isstatistically different from all other cultivars in that test (Table 3).

TABLE 3 Zoysias inflorescences compared to ‘SS-Z15’ conducted in 2010.Number of Total inflorescence Floral region Peduncle spikelets perSpikelet Cultivar length^(a) (mm) length^(b) (mm) length^(c) (mm)inflorescence^(d) length^(e) (mm) ‘SS-Z15’ 124.7 36.0 88.7 25.5 3.7 ‘ElToro’ 117.3 31.1 86.1 29.6 3.0 ‘Meyer’ 90.7 21.9 68.9 29.4 2.6 ‘BK-9’42.3 11.8 30.5 9.5 2.3 LSD (0.05) 7.7 2 7.1 2.6 0.1 ^(a)Totalinflorescence length is the mean of 25 observations per cultivarincluding the floral region and peduncle. ^(b)Floral region length isthe mean of 25 observations per cultivar ^(c)Peduncle length is the meanof 25 observations per cultivar measured from the base of the floralregion to the first node. ^(d)Number of spikelets per inflorescence isthe mean of 25 observations per cultivar determined by count.^(e)Spikelet length is the mean of 3 observations per inflorescence and75 per cultivar.

That which is claimed is:
 1. A new and distinct cultivar of Zoysia grassnamed ‘SS-Z15’, as herein illustrated and described, characterized byits distinctive and unique combination of several characteristics suchas: light green color, course texture, wide leaf blade with relativeshort blades, long white inflorescences, and green stolons.